This invention is an improvement of the invention reflected in our U.S. Pat. No. 5,029,605 (1991), entitled Fluid Vessel Overflow System.
The need for the present inventive system, as set forth herein, has developed as a result of development and testing of the invention of our said U.S. Pat. No. 5,029,605, and in response to needs of the marketplace which have arisen and which are addressed by the present improvement. The incorporation of such new areas into our system of control of fluid vessel overflows results in a system having an enhanced safety and cost-effectiveness in residential application.
More particularly, during the period since the grant of our said U.S. Pat. No. 5,029,605, that is, since July, 1991, patents have been granted to third parties which provide for the external connection of the various and sundry leak detection, energy source cutoff, and user signalling means. In other words, the prior art as it has developed since 1991, has entailed the removal of certain of the elements of our 1991 system, e.g., the solenoid means and liquid detection means, from the envelope defined by our fluid-tight peripheral housing, for the purpose of elaborating the function of the solenoid and liquid detection means, typically through the use of integrated circuitry and computer control means. Representative of such efforts are the patents to Furr, that is, U.S. Pat. Nos. 5,315,291 and 5,334,973, both of which entail the use of external electrical and mechanical means requiring external elements such as wiring, mechanical drive means, metallic foil, and external soldering to install the same. One result of systems such as Furr is that such systems cannot be economically built and sold in the residential market. Accordingly, while complex electrical and mechanical improvements of our 1991 system may exhibit certain value in large special purpose commercial and industrial structures, they are economically and technically infeasible to use or sale in a typical residential context.
Also, the prior art, as is known to the within inventors, does not provide a simple and cost-effective means of terminating the energy source of the system in the event of a tank leak, nor does it provide a means of assuring the internal integrity of the vacuum within the fluid vessel. That is, without a means of assuring maintenance of the internal vacuum (notwithstanding a leak or break in the liquid vessel), air in the plumbing, external to the hot water tank will attempt to occupy the water-containing volume of the hot water tank thereby accelerating the rate of the leak until most of the entire volume of the peripheral containment housing has been filled with water. It is the importance of maintaining the integrity of the vacuum within the liquid vessel (hot water tank) in the event of a leak therein has not been fully recognized by the art, this particularly in systems in which the safety means thereof are mechanically and electrically integrated into the envelope of the fluid vessel or are connected immediately thereabove to the input and/or output lines of the tank as a part of the original installation of the liquid vessel or hot water tank.
Other examples in the art of leak detection and leak management apparatus which make use of complex external electromechanical systems is reflected in U.S. Pat. No. 5,345,224 to Brown; No. 5,357,241 to Welch, and No. 5,428,347 to Barron. It is, accordingly, the need which has developed in the art for an effective integrated fluid vessel overflow system and which is cost-effective for use in the residential area, that has given rise to the instant invention.